AuthorTopic: Tell me what you see in these phase response graphs (Read 8999 times)

I've been working with REW software to get an idea of what a couple speakers of mine look like at the high frequency crossover. Pictured are a couple screen shots of the response of a 12X2 and 15X2 bi-amped speaker. These are after playing with the high frequency driver polarity and time delay on the woofer.For these test the 12X2 crossover is 1700hz and the 15X2 is 1600hz.Set up outdoors, measurement mic on axis between woofer and horn about 8 foot from the speaker.

I've been working with REW software to get an idea of what a couple speakers of mine look like at the high frequency crossover. Pictured are a couple screen shots of the response of a 12X2 and 15X2 bi-amped speaker. These are after playing with the high frequency driver polarity and time delay on the woofer.For these test the 12X2 crossover is 1700hz and the 15X2 is 1600hz.Set up outdoors, measurement mic on axis between woofer and horn about 8 foot from the speaker.

It's hard to imagine what you're doing to get 16 phase wraps in 1 octave.

I was primarily interested in the phase response at the crossover and if I'm looking at it right I think it is at least somewhat "flat" through the crossover point and the area around it.

I really should have taken a screen shot of the before adjustment.

You're not looking at it right. That sawtooth display at the bottom is the phase response. It is about as far from "flat" phase response as it is possible to get.

Ideally it should be a flat horizontal trace, not a sawtooth showing dozens of 360º phase wraps in a single octave. As Merlijn said, your reference and test signals are in totally different time zones.

It's hard to imagine what you're doing to get 16 phase wraps in 1 octave.

Mike,

If you open up the measurement again, in the upper right, there is a button for Controls. Open that, and press Estimate IR Delay. After you adjust the Impulse Response, you will have the phase plot you expect.

What you are looking at is the phase wrap of the delay caused by the travel time through the air between your speaker and microphone (as well as any measurement latency).

If you open up the measurement again, in the upper right, there is a button for Controls. Open that, and press Estimate IR Delay. After you adjust the Impulse Response, you will have the phase plot you expect.

What you are looking at is the phase wrap of the delay caused by the travel time through the air between your speaker and microphone (as well as any measurement latency).